html,body{
    margin: 0;
    padding: 0;
    font-size: 10px;
}
body{
    width: 100%;
    height: 100%;
}
main{
    width: 100%;
    height: 100%;
    /*min-width: 320px;*/
    background: url('../img/bj.png');
}
div:nth-child(1){
    width: 15rem;
    height: 20rem;
    background: url('../img/logo.png');
    background-size: 100%  100%;
    position: relative;
    top: 14.1rem;
    margin:  0 auto;
}
div:nth-child(2){
    width: 24rem;
    height: 4rem;
    margin: 22.1rem auto 0;
    background: url('../img/az.png');
    background-size: 100%  100%;
}
div:nth-child(3){
    width: 24rem;
    height: 4rem;
    background: url('../img/ios.png');
    background-size: 100%  100%;
    margin: 20px auto;
}
@media screen and (max-width: 375px) {
    html {font-size: 6px;}
}
@media screen and (min-width: 375px) {
    html {font-size: 11.71875px;}
}
@media screen and (min-width: 414px) {
    html {font-size: 12.9375px;}
}
@media screen and (min-width: 768px) {
    html {font-size: 24px;}
}
@media screen and (min-width: 1024px) {
    html {font-size: 32px;}
}